Vibratory screen



Feb. 2, 1937-. H, H, RUMPELV ET AL 2,069,331

VIBRATORY SQREEN Filed Aug. 13, 1934 3 Sheets-Sheet 2 A TT ORNE Y Feb.2, 1937. l H, H' RUMPEL Er AL 2,069,331

VIBRATORY SCREEN l Filed Aug. 13. 1 954 3 sheets-sheetv s j INVENTORS4BY Q,

ATTORNEY.

Patented Feb. 2, 1937 UNITED STATES PATENT OFFICE VIBRATORY SCREENconsin Application August 13, 1934, Serial No. 739,516

8 Claims.

The present invention relates in general to improvements in the art ofseparating or grading granular materials, and relates more speciiicallyto various improvements in the construction and 5 operation of vibratoryscreens or the like.

Generally dened, an object of the present invention is to provide adurable and readily adjustable vibratory screen structure, which ishighly efficient under various conditions of use.

l The matter of constructing a durable and effective vibratory screen,operable at desirably high speed and with minimum destructive effectupon bearings, joints, and supports, especially when the screen is to beoperated under variable l conditions, presents many perplexing problemswhich cannot be readily solved. Altho many different forms and types ofvibratory screens have heretofore been proposed and are now beingmarketed, all of these prior devices are deficient in one or morerespects, and fail to func- 20 tion eiiiciently under all conditions ofoperation to which such apparatus is normally subjected. Most of theprior screening mechanisms fail to provide for uniform and mosteffective vibration thru-out the entire screening area by failing toincorporate properly located resilient supports for the screening decks.Then too, the prior screen structures do not provide sufficientflexibility in the adjustment of parts, so as to most effectively meetvariable operating conditions, while maintaining most eflicientvibration regardless of the position of adjustment. 'I'he prior screens,moreover, do not sufficiently guard the frames and driving mechanismsagainst exlived and require frequent, costly repairs; and are, in mostcases, so complicated that the frequent and necessary repairs entailextreme time losses. These are only some of the numerous objectionablefeatures which cooperated to` make all of the prior vibratory screensmore or less objectionable and unable to satisfactorily meet commercialrequirements.

It is therefore a more specific object of the present invention toprovide an improved vibratory screen which overcomes all of theobjections existing in prior structures of this general class.

Another specific object of the invention is to provide an improvedresilient support for one or more screening decks, which insuresmaintenence of uniform and most eflicient vibration thruout the entirescreening area.

A further specic object of the present invention is to provide simpleand effective mechanism cessive stresses, and are therefore relativelyshort for Varying the number of decks and the angularity of a screen,While retaining substantially equal resilient reaction on all portionsof the screening surface.

Still another specic object of the invention is 5 to provide an improvedmounting for a Vibrating screen, whereby the driving or operatingmechanism therefor is substantially relieved from the dead weight of thescreening elements.

An additional specific object of the invention is the provision of adurable screen' assemblage wherein the frame and driving mechanisms arerelieved from undue stresses due to non-uniformity in loading and othercauses.

A further specific object of the invention is to provide a screeningstructure which canV be readily and quickly repaired, and wherein thescreening units may be conveniently replaced by others in order to varythe capacity and range of grading.

The present invention furthermore contemplates provision of a vibratoryscreen assemblage which is compact and can be mounted on relativelyfrail supports without danger of imparting destructive vibration to thesupporting structure.

The invention additionally involves the provision of an improvedvibrating unit for screens or the like, which is durable in structure,and which may be bodily removed from one screen assembly and applied toanother.

The improvement also contemplates the provision of screening mechanismoperable at any desired speed and upon materials having a Wide range ofcharacteristics, and which may be manufactured and operated at minimumcost.

These and other specific objects and advantages will be apparent fromthe following detailed description.

A clear conception of an embodiment of the invention, and of the mode ofconstructing, in- 40 stalling, and of operating vibratory screens builtin accordance with the improvement, may be had by referring to thedrawings accompanying and forming a part of this specification, in whichlike reference characters designate the same or similar parts in thevarious views.

Fig. l is a side elevation of'a double deck vibratory screen embodyingthe improvement;

Fig. 2 is a top view of the double deck vibratory screen of Fig. 1; 50

Fig. 3 is an end view of the screen structure,

looking toward the discharge end thereof;

Fig. 4 is an enlarged, fragmentary section taken transversely of thescreen assembly thru one set of side bearings of the vibrating unit;

Fig. 5 is a perspective view of one of the vibrating units, removed fromthe screen assembly;

Fig. 6 is an enlarged, fragmentary section thru the discharge endsupporting spring assemblage, the section being taken along the line 6-6of Fig. 2;

Fig. 7 is a perspective view of the completely assembled screenstructure, looking toward the delivery end and driving side; and

Fig. 8 is another perspective view of the assembled screen structure,looking toward the feed end and opposite side.

While the invention has been illustrated and described herein as beingspecically applied to a double-deck, inclined, spring-supported screenadapted to be belt driven, it is not intended to limit the scope by suchspecific disclosure since some of the improved features may also beapplicable to other types of screening apparatus.

Referring to the drawings, the improved vibratory screen shown thereincomprises in general a rectangular, normally iixed frame or member I0adapted to be mounted directly upon a suitable support or to besuspended by cables from overhead structure; a vibrating unit II mountedin anti-friction side bearings I2 carried by the medial portions of theopposite sides of the frame member I0; and one or more superimposed,inclined screen decks I3, I4 mounted between spaced side plates I5, theupper medial portions of which are rigidly but detachably secured to theunit I I.

The frame member I0 may be formed of heavy channel bar sections rigidlyunited by means of corner angles I5 riveted and welded in place, andthis member is preferably disposed in a substantially horizontal plane,as shown in Figs. l, 7, and 8. The interior of the frame member I0 isentirely free from obstruction for reception of the screening elements,and the side bars of this frame may be provided with attaching orsuspending holes as shown in Fig. 2.

The vibrating unit II is illustrated in detail in Figs. 4 and 5, andconsists of a rotary horizontal shaft I6 coacting directly with the sidebearings I2 which are carried by the frame member I0, and spanning thismember; a driving pulley I'I attachable to either of the projecting endsof the shaft I6; a pair of eccentrically weighted, balancing rotors I8for the eccentrics secured to the shaft I6 adjacent the bearings I2;spaced side plates I9 suspended from the shaft I 6 thru eccentric rollerbearings 26; and a plurality of rigid elements connecting the two sideplates I9 so as to maintain the same in definitely spaced relationship.The pulley II may be either of the cone or grooved type and isdetachably connectable to either end of the shaft I6 by means of a key2I and cap screws 22 coacting with a clamping plate 23. The rotors I8attached to the rotating shaft I6 by keys 24, are provided withbalancing weights 25 composed of a plurality of laminations, any numberof which may be added or removed so as to effect perfect balancing ofthe eccentrics. The inner eccentric races 26 of the bearings 20 are alsoattached to the shaft I6 by means of the keys 24, and the outer rings2'I of these bearings are carried by annular brackets 28 which arerigidly connected to the suspension plates I9 by means of bolts 29 asshown in Figs. 4.- and 5. The adjacent sides of the brackets 28 arerigidly interconnected by means of a tubular connecting element 30 whichsurrounds and coniines the medial portion of the shaft I6, and the bolts29 coacting with ring members 3I attached by welding to the ends of thetubular element 30, also serve to establish such interconnection. Theside plates I9 are additionally rigidly connected at points remote fromthe shaft I6 and element 30, by means o1 two relatively inclined,channel-shaped plate elements 32 bolted to angle irons 33 which arerml'y attached to the inner sides of the plates I9, thereby providing arigid screen supporting cradle which is suspended from the rotary shaftI 6 thru the eccentric roller bearings 20.

The screen deck mounting plates I5 are adapted to be attached at theirmedial upper portions directly to the lower elongated ends of the cradleplates I9, by means of a series of removable bolts 34 as illustrated inFig. l. These mounting side plates are spaced apart and rigidlyinterconnected by means of an upper flat beam 35 at the feed end, aU-shaped beam 36 at the discharge end, and a series of parallel,transverse spacer bars 3'I located intermediate said ends and beneaththe screen decks I3, I4. The upper and lower screen decks I3, I4 arermly but removably attached to the side plates I5 by means of bolts 38coacting with clamping strips 39, and these decks may be disposed eitherparallel or at a slight angle to each other. The use of the U- shapedspacing beam 36 at the delivery end of the screen provides clearance forunobstructed discharge of the separated materials.

The resilient mountings for the opposite ends of the screen deck supportare associated with the medial portions of the spacer beams 35, 36respectively and with the adjacent medial portions of the transverse endbeams of the supporting frame member I 0. The feed end resilientmounting comprises one or more laterally deflectable coil springs 40,the lower ends of which rest upon a vertically adjustable, horizontallydisposed angle plate 4 I and the upper ends of which react against ahorizontally disposed angle plate 42 rigidly attached to andsubstantially forming a part of the upper at spacer beam 35. rThe lowerand upper ends of the springs 4D are fitted over confining lugs 43, 44secured to the angle plates 4i, 42 respectively; and the lower plate 4Iis vertically adjustably connected to spaced, flat plates 45 rigidlyattached to the frame member I0, by means of adjusting bolts 46. Thedischarge end resilient mounting comprises one or more laterallydeflectable coil springs 41, the lower ends of which rest upon avertically adjustable, horizontally disposed angle plate 46, and theupper ends of which react against a horizontally disposed angle plate 49forming the upper, medial portion of the U-shaped spacer beam 36. Thelower and upper ends of the springs 4l are again tted over conning lugs43, 44 secured to the angle plates 48, 49 respectively; and the lowerplate 48 is vertically adjustably connected to laterally spaced angularplates 50 rigidly attached to the frame member IIJ, by means ofadjusting bolts` 46. It is to be noted that these spring mountings forthe screen ends are conned to the central, longitudinal plane of thescreen assemblage; and that by properly adjusting the bolts 46, thesprings 40, 4'I may be caused to carry the dead weight of the vibratoryscreen structure, thereby entirely relieving the bearings I2, 26 of thisweight. It is also to be observed that both the eccentric bearings 20and the main bearings I2 are of the antifriction type and areeffectively guarded and packed against the entry of dust and otherforeign matter.

During normal operation of the improved screening mechanism, the framemember I0 is properly supported in substantially horizontal position, aslshown in Fig. 1,- and the shaft I6 of the vibrating unit is beingrotated at high speed by power applied to the pulley I1. The rotatingshaft I 6 carries with it the eccentric bearing races 26 and theirbalancing rotors I8, and the eccentrics 26 impart rapid vibratory motionto the screen decks I3, I4 thru the suspension plates ISandside platesI5, while the rotors I8 prevent transmission of the vibrations to theframe I0. The material to be screened is delivered to the upper surfaceof the upper deck I3 over the end beam 35, and travels downwardly overthis upper deck. During its advancement over the upper deck I3, allparticles of material which are capable of passing thru this deck aredeposited upon the upper surface of the lower deck I4, and the oversizematerial from the upper deck I3 is eventually discharged at the lowerend thereof and is precipitated into a suitable receiving compartment.The material passing along the lower deck I4 is separated into thefines, which pass thru this deck, and the intermediate size material,which is eventually discharged from the lower end of the deck I4 intoanother suitable receiving compartment.

By proper adjustment of the bolts 46, the end springs 4U, 41 may readilybe caused to substantially relieve the bearings I2, 20 of the dead loador weight of the vibratory parts, and of some of the weight of thematerial. When the material is deposited upon the screen decks, some ofthe weight thereof may be borne by the bearings I2, 20, but thesebearings may, by proper adjustment of the springs 40, 41, be practicallyrelieved of pressure other than that introduced by the driving belt,when the screen is unloaded.

The disposition of the resilient supports comprising the springs 40, 41,near the central, longitudinal plane of the screen structure, causesuniform distribution of the pressures upon these supports. By properadjustment of the bolts 46, it is also possible to vary the inclinationof the screen decks, thereby varying the rapidity with which thematerial travels along these decks. The horizontal disposition of theframe member I permits convenient mounting of the screen structure uponany kind of a foundation, and the rate of travel of the material alongthe screen decks may also be varied by slightly, longitudinally tiltingthe supporting frame I0. The location of the vibrating bearings 20 andthe counterbalancing rotors I8 therefor, on opposite sides of the planeof support of the screen decks, also results in the impartation ofminimum vibration to the frame member I0.

The vibrating unit II may be conveniently removed from the screen deckassembly by releasing the bolts 34, and a substitute deck assemblyhaving either a greater or lesser number of decks or decks of differentmesh, may then be substituted for the removed assemblage. This changecan be made quickly and with minimum inconvenience. The cradle of theunit II is of extremely rigid construction by virtue of the provision ofthe connecting tubular element 30 surrounding the shaft I6, and theadditional provision of the U-shaped bracing plates 32 disposed remotefrom the tubular element 30. The extreme width of the side plates I9 ofthe unit II also insures maximum rigidity in the entire structure andprevents possible weaving of the screen deck supporting framesconsisting of the side plates I5 and the end beams 35, 36. The balancingrotors I8, disposed closely adjacent to the screen vibrating eccentrics26, prevent unclesirable transmission 'of vibrations to the mainsupports and thereby p-rotect the foundations.

From the foregoing disclosure, it will be apparent that the presentinvention provides an extremely simple and highly eiiicient vibratoryscreen structure which is relatively flexible in use and adaptation. Theassemblage is readily adjustable so as to permit operation with minimumpower consumption and with minimum destructive vibration and can beconveniently mounted upon any desired type of supports. The improvedvibratory screen has proven highly successful in actual commercialoperation and is extremelyy durable in construction.

It should be understood that it is not desired to limit the invention tothe exact details of construction and to the precise mode of operationherein shown and described, for various modifications within the scopeof the claims may occur to persons skilled in the art.

It is claimed and desired to secure by Letters Patent:

1. A vibratory screen, comprising, a normally fixed substantiallyhorizontal frame support, an inclined screen member extending downwardlythrough said support, vibrating means carried by said support onopposite sides of said member and coacting with the latter between itsupper and lower ends, and vertically adjustable spring means coactingwith said member and with said support only at the medial portions ofthe ends of said member.

2. A vibratory screen, comprising, a stationary supporting frame, anangularly adjustable inclined screen deck located near said frame,vibrating means carried by said frame and extending across and coactingwith said deck intermediate its upper and lower ends, verticallyadjustable spring means coacting with said deck and with said frame onlynear the central longitudinal plane of said deck, and means foradjusting said spring means so as to relieve said vibrating means fromthe dead weight of said deck.

3. In a vibratory screen., a normally fixed frame having spaced sidebeams interconnected by end beams, a shaft mounted in bearings c-arriedby said side beams, an inclined screen deck suspended from said shaftand extending downwardly through said frame between said side and endbeams, and vertically adjustable resilient supports coacting with themedial portions only of said end beams and of the ends of said deck.

4. In a vibratory screen, a rotary shaft, spaced eccentrics carried bysaid shaft, side plates suspended from said shaft thru said eccentrics,a tubular element surrounding said shaft and rigidly connecting saidside plates near said shaft, plate elements rigidly interconnecting saidside plates remote from said tubular element to form a cradle, and ascreen deck having permanent side supports detachably suspended fromsaid cradle plates.

5. In a vibratory screen, a rotary horizontal shaft, spaced eccentricsc-arried by the medial portion of said shaft, vertical side platessuspended from said shaft thru anti-friction bearings coacting with saideccentrics, a tubular element rigidly interconnecting said plates nearsaid eccentrics, U-shaped plate elements rigidly interconnecting saidplates remote from said eccentrics to forms a cradle, and an inclinedscreen deck having permanent side supports detachably suspended fromsaid cradle side plates.

6. In a vibratory screen, a rotary shaft, ec-

centric means carried by said shaft, spaced side plates suspended fromsaid shaft thru said eccentric means, an element rigidly interconnectingsaid plates near said eccentric means, other elements rigidlyinterconnecting said plates remote from said eccentric means to form acradle, a screen deck having permanent side supports detachablysuspended from said cradle plates, and means coacting with said deck forrelieving said eccentric means from the dead Weight of said deck and ofsaid plates and the interconnecting elements.

7. A vibratory screen, a rotary shaft, bearings for said shaft,eccentric means carried by said shaft, a cradle suspended from saidshaft thru said eccentric means, a screen deck sus- HARVEY H. RUMPEL.ALEXANDER L. MUNRO.

